private void ReadARGB()
        {
            if (_dataset.RasterCount < 4)
            {
                throw new GdalException("ARGB Format was indicated but there are only " + _dataset.RasterCount + " bands!");
            }
            _alpha = _red;
            _red = _dataset.GetRasterBand(2);
            _green = _dataset.GetRasterBand(3);
            _blue = _dataset.GetRasterBand(4);

            int tw = TileCollection.TileWidth;
            int th = TileCollection.TileHeight;
            for (int row = 0; row < TileCollection.NumTilesTall(); row++)
            {
                for (int col = 0; col < TileCollection.NumTilesWide(); col++)
                {

                    int width = TileCollection.GetTileWidth(col);
                    int height = TileCollection.GetTileHeight(row);
                    MWImageData id = new MWImageData(width, height);


                    Bitmap image = new Bitmap(width, height, PixelFormat.Format32bppArgb);

                    byte[] red = new byte[width * height];
                    byte[] g = new byte[width * height];
                    byte[] b = new byte[width * height];
                    byte[] a = new byte[width * height];

                    _red.ReadRaster(col * tw, row * th, width, height, red, width, height, 0, 0);
                    _green.ReadRaster(col * tw, row * th, width, height, g, width, height, 0, 0);
                    _blue.ReadRaster(col * tw, row * th, width, height, b, width, height, 0, 0);
                    _alpha.ReadRaster(col * tw, row * th, width, height, a, width, height, 0, 0);

                    BitmapData bData = image.LockBits(new Rectangle(0, 0, Width, Height), ImageLockMode.ReadWrite,
                                                       PixelFormat.Format32bppArgb);
                    Stride = bData.Stride;
                    image.UnlockBits(bData);
                    byte[] vals = new byte[Width * Height * 4];
                    int stride = Stride;
                    const int bpp = 4;
                    for (int r = 0; r < height; r++)
                    {
                        for (int c = 0; c < width; c++)
                        {
                            vals[r * stride + c * bpp] = b[r * width + c];
                            vals[r * stride + c * bpp + 1] = g[r * width + c];
                            vals[r * stride + c * bpp + 2] = red[r * width + c];
                            vals[r * stride + c * bpp + 3] = a[r * width + c];
                        }
                    }
                    id.Values = vals;
                    id.WriteBytes();
                    TileCollection.Tiles[row, col] = id;
                }
            }
            SetTileBounds(Bounds.AffineCoefficients);
        }
        private void ReadGrayIndex()
        {

            int tw = TileCollection.TileWidth;
            int th = TileCollection.TileHeight;
            for (int row = 0; row < TileCollection.NumTilesTall(); row++)
            {
                for (int col = 0; col < TileCollection.NumTilesWide(); col++)
                {

                    int width = TileCollection.GetTileWidth(col);
                    int height = TileCollection.GetTileHeight(row);
                    MWImageData id = new MWImageData(width, height);
                    byte[] red = new byte[width * height];
                    _red.ReadRaster(col * tw, row * th, width, height, red, width, height, 0, 0);
                    Bitmap image = new Bitmap(width, height);
                    BitmapData bData = image.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.ReadWrite,
                                                       PixelFormat.Format32bppArgb);
                    Stride = bData.Stride;
                    image.UnlockBits(bData);
                    byte[] vals = new byte[width*height*4];

                    int stride = Stride;
                    const int bpp = 4;

                    for (int r = 0; r < height; r++)
                    {
                        for (int c = 0; c < width; c++)
                        {
                            vals[r*stride + c*bpp] = red[r*width + c];
                            vals[r*stride + c*bpp + 1] = red[r*width + c];
                            vals[r*stride + c*bpp + 2] = red[r*width + c];
                            vals[r*stride + c*bpp + 3] = 255;
                        }
                    }
                    id.Values = vals;

                    id.WriteBytes();
                    TileCollection.Tiles[row, col] = id;
                }
            }
            SetTileBounds(Bounds.AffineCoefficients);
        }